ProgramNode(0...37)(
  [],
  StatementsNode(0...37)(
    [DefNode(0...15)(
       (4...5),
       nil,
       ParametersNode(6...9)(
         [RequiredParameterNode(6...9)(:foo)],
         [],
         [],
         nil,
         [],
         nil,
         nil
       ),
       nil,
       [:foo],
       (0...3),
       nil,
       (5...6),
       (9...10),
       nil,
       (12...15)
     ),
     DefNode(17...37)(
       (21...22),
       nil,
       ParametersNode(23...31)(
         [RequiredParameterNode(23...26)(:foo),
          RequiredParameterNode(28...31)(:bar)],
         [],
         [],
         nil,
         [],
         nil,
         nil
       ),
       nil,
       [:foo, :bar],
       (17...20),
       nil,
       (22...23),
       (31...32),
       nil,
       (34...37)
     )]
  )
)
